Lamp holder including a centrally operated switch by means of carrier current transmission

Abstract

A track lighting system including remote on-off control of the lighting element, carrier-current transmitter for transmitting carrier-current signals over power lines, a bipolar rail for the electric power connected to the signal transmitter, a lamp holder comprising a first section cooperating with the rail, an intermediate section housing, a receiver for receiving the carrier-current signals and connected to a power switch, and an end section for supporting a lighting element, and selecting apparatus housed in the intermediate section for adjusting the receiver so that the receiver is responsive only to one among a plurality of the carrier-current signals sent over the power lines through the bipolar rail. The selecting apparatus includes a comb connection associated with the receiver and a movable contact for selecting the one signal to which the receiver is to be responsive.

I claim: 
     
       1. A track lighting system having means for the remote on-off control of the lighting element, said system comprising: carrier-current transmitter means for transmitting carrier-current signals over power lines;   a bipolar rail for the electric power connected to the signal transmitter;   a lamp holder comprising a first section cooperating with said rail, an intermediate section housing, a receiver for receiving said carrrier-current signals and connected to a power switch, and an end section for supporting a light element;   selecting means housed in said intermediate section for adjusting said receiver so that said receiver is responsive only to one among a plurality of the carrier-current signals sent over the power lines through said bipolar rail;   said selecting means comprising a comb connection associated with said receiver and a movable contact means for selecting the one signal to which said receiver is to be responsive.   
     
     
       2. A track lighting system according to claim 1, wherein said signal transmitter comprises an oscillator coupled to an encoder controlled by a control panel and means for coupling a signal generated by said oscillator to the power lines to constitute the carrier-current signals sent to said receiver. 
     
     
       3. A track lighting system according to claim 2, wherein said receiver comprises means for picking the signal of said oscillator travelling over the power lines, decoder mans for identifying the one signal selected by said selecting means to which said receiver is to be responsive in order to control said power switch.